 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B747-400 captain reported his airline was using northern hemisphere airports as enroute re-dispatch destinations and as alternates despite notams precluding the use of their approaches due to excessive differences between the actual current magnetic variation and those utilized by FMS databases and chart makers.he declared he has been repeatedly rebuffed by all responsible parties in his attempts to ensure that magnetic variations utilized by aircraft navigation databases and aero charts are regularly updated so as to comport to current actual variations. He believes differences at some remote airports are sufficient to result in cftt or even CFIT events.
| Attributes | |
| ACN | 1014746 |
| Time | |
| Date | 201205 |
| Local Time Of Day | 1201-1800 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Aircraft 1 | |
| Make Model Name | B747-400 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Parked |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Navigation Database |
| Person 1 | |
| Function | Captain Pilot Not Flying |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Experience | Flight Crew Last 90 Days 0 Flight Crew Total 15000 Flight Crew Type 3000 |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical Deviation - Procedural Other / Unknown Inflight Event / Encounter CFTT / CFIT |
Narrative:
Our anc NOTAM 13/5 disallowed CAT 1; 2 or 3 ILS approaches to minima due to onboard [FMS navigation database] magnetic variation in [excessive] deviation from actual airport variation. Anc was nonetheless; listed as intermediate destination. One of our intermediate alternates listed was edf which has the same magnetic variation problem as anc yet there are no NOTAMS for edf prohibiting ILS approaches to CAT 1; 2 or 3 minima.en route in northwest canada and alaska near anc; the aircraft database variation data for locations deviates from current map variation by up to 8 degrees. Flight crews are; thus; unable to check courses in aircraft vs. Flight plan for magnetic accuracy when passing waypoints. As a result; true courses appear to match flight plan true courses while the database magnetic variations appear to be in gross error vs. Current navigation maps. Please advise how we are to audit flight plan courses vs. Maps.
Original NASA ASRS Text
Title: A B747-400 Captain reported his airline was using Northern hemisphere airports as enroute re-dispatch destinations and as alternates despite NOTAMs precluding the use of their approaches due to excessive differences between the actual current magnetic variation and those utilized by FMS databases and chart makers.He declared he has been repeatedly rebuffed by all responsible parties in his attempts to ensure that magnetic variations utilized by aircraft navigation databases and aero charts are regularly updated so as to comport to current actual variations. He believes differences at some remote airports are sufficient to result in CFTT or even CFIT events.
Narrative: Our ANC NOTAM 13/5 disallowed CAT 1; 2 or 3 ILS approaches to minima due to onboard [FMS Navigation Database] magnetic variation in [excessive] deviation from actual airport variation. ANC was nonetheless; listed as intermediate destination. One of our intermediate alternates listed was EDF which has the same magnetic variation problem as ANC yet there are no NOTAMS for EDF prohibiting ILS approaches to CAT 1; 2 or 3 minima.En route in Northwest Canada and Alaska near ANC; the aircraft database variation data for locations deviates from current map variation by up to 8 degrees. Flight crews are; thus; unable to check courses in aircraft vs. flight plan for magnetic accuracy when passing waypoints. As a result; true courses appear to match flight plan true courses while the database magnetic variations appear to be in gross error vs. current navigation maps. Please advise how we are to audit flight plan courses vs. maps.
Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.